David P. Wick Clarkson University

1. Traditional vs. Problem Based Approaches to Teaching Introductory Physics2001 Science Educators’ Conference David P. Wick Clarkson University Acknowledgements: Michael W. Ramsdell Joseph Hruska

2. A Set of Goals Established by theAmerican Association of Physics Teachers • A strong program should emphasize experiential learning, open-ended problem solving and development of analytic and collaborative learning skills. • Students should have the opportunity to experience all aspects of scientific analysis including the design, development and executionof a successful experimental investigation.

3. Students should have access to experiences that encourage the development of verbal and mathematical models used to mimic the natural world. • A strong program should provide exposure to experimental, theoretical and numericaldevelopment, allowing students to truly master a variety of basic skills in problem solving and data analysis. [i]American Association of Physic Teachers, "Goals of the Introductory Physics Laboratory," Am. J. Phys. 66, 483-485 (1998).

4. Outstanding challenges for the scientific community are to: • Find innovative methods for achieving these goals. • Develop tools for assessing the performance of our students and the effectiveness of our methods.

5. Physics Education Research is a work in progress… • PER has logged over three decades worth of scientific investigation with attention given to: - Identification of student misconceptions. - Development of pedagogical strategies to provide a more effective learning experience for students. - Assessment of educational approaches.

6. Misconceptions or Preconceptions? • Student minds are not blank slates. • Many students defend their beliefs from the high seat of experience. Student difficulties are not reflections of “stupidity”, but rather deeply rooted and seemingly logical consequences of perception reinforced with personal experience. [2]Aarons, A. B.,Teaching Introductory Physics, John Wiley & Sons (1997). • Examples are well documented.

7. Example: The Concept of Velocity Ball A Ball B Question: Do these two balls ever have the same speed? Study: 300 student interviews at University of Washington (calculus-based physics course). Misconception: The balls have the same speed at the moment one 40% passes or is next to the other. Students associate “same speed” with “passing” or “same position.” [3]McDermott, L. C.,“Research on Conceptual Understanding in Mechanics,” Phys. Today, 37, 24-32 (1984).

8. Example: Velocity vs. Speed Question: A ball is thrown vertically upward from ground level with an initial speed vo. The ball reaches a maximum height d and returns to ground level. Which statement is TRUE? 43% A)     The initial velocity is equal to the final velocity; 32% B)The average velocity for the entire flight is zero; 9% C)     The acceleration on the way down is greater than the acceleration on the way up; 16% D)     The average acceleration for the entire flight is zero. Study: 500 student responses at Clarkson University – Exam I (calculus-based physics course). Misconceptions: “Velocity” and “Speed” are interchangeable. Acceleration depends on direction of motion.

9. We must eliminate misconceptions, but students will only accept a scientific concept if: • They understand the concept. • It is believable. • It is useful. • It conflicts with their current beliefs. “Understanding the way students and scientists think is the key to developing more effective methods of science teaching and is itself an intellectual challenge.” [4]Reif, F.,“Scientific Approaches to Science Education,” Phys. Today, 39, 48-53 (1986).

10. Current Strategies:Interactive Engagement • Lecture-based (Peer instruction, Interactive Lectures, …) • Recitation-based (Tutorials, Cooperative Problem Solving, …) • Lab-based (Projects, Problems, Simulations, …) • Combination (Physics by Inquiry, Workshop Physics, Physics Studio …) [5]Redish, E.,“New Models of Learning and Teaching,” Conference of Physics Department Chairs (1997).

11. A typical first-exam grade distribution in Physics I at Clarkson University: The bi-modal nature is indicative of a well prepared and an ill prepared group.

12. Traditional Laboratory Experience Typical Laboratory Manual Contains: Title Apparatus – Description of equipment Introduction – Theory, figures, equations Procedure – Step 1, Step 2, … Tables and Graphs, etc.

13. Current Approach: Lab/Recitation-based • Modification of the traditional laboratory / recitationto incorporate a problem based learning experience with an emphasis on open-ended problem solving. • Provide students with the opportunity to: - Formulate verbal models - Develop mathematical models (theoretical and numerical) - Design experimental procedures - Test the predictive capability of their models.

14. Problem Based LearningPhysics Team Design Program • Current Participation: 10-15 % of class • Lecture Component – Traditional • Lab/Recitation Component – Problem Based “Modeling is the name of the game in the Newtonian World” [6]Hestenes, David,“Modeling Games in the Newtonian World,” Am. J. Phys. 60, 732-748 (1992).

15. Traditional vs. Problem Based Approaches • Physics I – Modeling the Motion of a Matchbox Car • Physics II – Modeling the Motion of an Electric Train

16. Assessment:Force Concepts Inventory • David Hestenes (Arizona State University) and others have developed a quantitativeassessment tool for checking a student's understanding of basic concepts in physics. • FCI topics cover the fundamental issues and concepts in Newtonian dynamics. • FCI distractors (wrong answers) are “malicious” -- they are based on research that exploits students' most common misconceptions.

17. Results of the FCI are Disappointing! • Richard Hake (Indiana University) conducted a study of 62 classes (6542 students) from around the country. He showed that for a wide range of initial pre-test scores, the fractional gain is similar for classes of similar instructional method. • For Traditionalclasses: h ~ 0.23 +/- 0.04 • For IE classes: h ~ 0.48 +/-0.14 [7]Hake, Richard,“Interactive Engagement vs. Traditional Methods,” Am. J. Phys. 65, (1995).

18. Force Concepts Inventory (FCI)

19. Team Design Produced Significantly Higher Gains ThanTraditional Labs

20. Comparison Group?Team Design Produced Significantly Higher Gains Than a Comparison Group

21. Best of the Rest?– High SATTeam Design Even Produced Higher Gains Than the High SAT Group

22. Comparison Table

23. Comparison Table

24. Comparison Table

25. Matchbox Car Project

26. “Modeling the Motion of a MatchboxTM Car” Problem Statement: Develop a theoretical model describing the motion of a MatchboxTM car racing down an arbitrarily shaped track. Your model should describe the velocity of the car at any point along the track. (Identify the most important effects that should be included in this model). Design an experimental procedure to evaluate the predictive capability of your model.

27. Facts:A typical MatchboxTM car has a die-cast body, two axles, and four hard plastic wheels, with a total mass (m) of approx. 50 g. The combined mass of the wheels is less than 3 % of the total mass of the car. The plastic wheels rotate on the axle through direct contact with a sliding type motion. Air resistance can be accentuated by mounting a shield of varying area.

28. Developing a Theoretical Model • Consider the forces acting on the car: Frictional Model Drag Force Model • Applying Newton’s Second Law will allow us to develop a model for the velocity of the car.

29. Case by Case Assumptions Case Agravitational potential andkinetic energies Case Bsliding friction Case Ctrack shape Case Dair resistance

30. Hierarchical Structure of Solutions This multi-level approach illustrates how each successive stage in model development provides a correction to the previous one.

31. Designing an Experimental Procedure Measuring friction and air drag We can extract values for and kby measuring the velocity of the car at different points along a flat, horizontal track using a series of photogates.

32. Experimental Results for a Level Track 0.049 (No Shield) k=1.48 x 10-4(kg/m) (No Shield)

33. What About an Arbitrary Track?

34. Comparing Theory to Experiment

35. Sample Challenge Session Goal:Predict where your car will first come momentarily to rest.

36. Electric Train Project

37. Model Rocket Project